    "ratio"
    (reify Decoder
      (decode [_ o] (/ (.get ^java.util.List o 0)
-                      (.get ^java.util.List o 1))))})
+                      (.get ^java.util.List o 1))))
+
+   "n"
+   (reify Decoder
+     (decode [_ o] (clojure.lang.BigInt/fromBigInteger
+                    (BigInteger. ^String o))))})
 
 (defn map-builder
   []

  (write w [#{1 2} #{1 2}])
  (write w (int-array (range 10)))
  (write w {[:a :b] 2})

  (def in (ByteArrayInputStream. (.toByteArray out)))



   clojure.lang.BigInt
   (reify Handler
     (tag [_ _] "n")
     (rep [_ bi] (str (biginteger bi)))
     (stringRep [this bi] (.rep this bi))
     (verboseHandler [_] nil))

   clojure.lang.Keyword
